Effect of fly-ash on mercury speciation in coal fired power plants

INOR 201

Samuel D. Fleischman, sfleischman@chem.ucsb.edu, Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93106-9510 and Susannah L. Scott, sscott@engineering.ucsb.edu, Departments of Chemical Engineering and Chemistry, University of California, Santa Barbara, Santa Barbara, CA 93106-5080.
80 tons of mercury are released to the atmosphere in the U.S. each year. Coal-fired power plants are responsible for over 60% of anthropogenic atmospheric emissions. The ability of existing pollution control devices to trap mercury is strongly dependent on its redox speciation: elemental mercury is volatile and insoluble, and is not effectively trapped in either particulate filters or scrubbers. Reactions which convert reactive gaseous mercury (RGM, with mercury in oxidation state II) or particulate mercury (non-volatile forms of Hg(II)) in the flue gas are therefore of interest because they have a direct bearing on the efficiency of mercury removal methods. We show that fly-ash from coal-fired power plants can catalyze the water-gas shift reaction. Hydrogen produced in this reaction reduces HgCl2, a model for RGM, and HgO, a model for particulate mercury, to Hg(0). The temperature thresholds for each of these reactions were investigated using gas-phase IR spectroscopy.
 

Environmental Aspects of Inorganic Chemistry
7:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007